Implement anchors for linking within a page

Requirements:
1/ Implement achors (like "#myanchor") so links can point to specific locations in a page.
2/ Headings and objects like images should have an implicit anchor that can be linked to.
3/ Allow linking to anchors in other pages without explicitly giving the page name (assuming anchor is globally unique)

There is seems to be a similarity between anchors and tags. The difference is that tags are used to group pages, in a category, while anchors are used to point at a specific object or location. So anchors should be unique location, while the same tag appear in multiple places.